FBI: Ivins held identical anthrax strain

Documents released Aug. 6, however, portray a person that most of his colleagues may not recognize. The FBI's allegations include a decades-long obsession with college sorority Kappa Kappa Gamma and other mental health issues.

In e-mails to an unidentified friend released by the government, Ivins talked about feeling dizzy and having a strange metallic taste in his mouth.

"Other times, it's like I'm not only sitting at my desk doing work, I'm also a few feet away watching me do it," he wrote in an e-mail on April 3, 2000.

The attacks of Sept. 11, 2001, appeared to affect him greatly. In December 2001, he sent a co-worker some poetry he had composed. "I'm a little dream-self, short and stout/ I'm the other half of Bruce – when he lets me out," one poem began.

The substantive aspect of the case against Ivins appears to be the product of the rapidly developing science of microbial forensics. Harnessing powerful computers and new genetic knowledge, this tool develops DNA fingerprints by looking for tiny mutations in the genetic makeup of otherwise-related strains of bacteria.

This new law enforcement tool received a large push from FBI efforts to solve the 2001 anthrax case. The government's years-long probe into the attacks has cost millions of dollars and been criticized both for its slow speed and for pointing wrongly toward another Ft. Detrick scientist, Steven Hatfill.

Hatfill was publicly named as a "person of interest" in the case, but has since won a judgemnt for millions of dollars from the government for false accusation.

The FBI now believes it has cracked the case with the aid of microbial forensics. But whether the genetic evidence would have stood up in a court of law will not now be tested.